In many industrial processes, a gas and a liquid are brought into intimate contact to achieve a transfer of solute gas to or from the liquid solvent.
Gas-liquid reactions with absorption and desorption are widely used in five main fields of the chemical industry, namely:
(i) Liquid phase processes: oxidation, hydrogenation, polymerization, etc. PA1 (ii) Gas scrubbing: removal of carbon dioxide, hydrogen sulphide, carbon monoxide, etc. PA1 (iii) Manufacture: sulphuric acid, phosphates, etc. PA1 (iv) Biological processes: aerobic fermentation, oxidation, etc. PA1 (v) Multi and two-phase flow: petrol refining, etc.
Typical examples of the equipment used for such reactions are packed columns, spray columns, plate columns or mechanically agitated vessels. The present invention is concerned with new apparatus which has been developed for the desorption of a gas using a liquid phase process where one gas is replaced in solution by another.
Known apparatus for extracting a dissolved first gas from a liquid comprises a liquid conduit for conveying the liquid; gas/liquid contacting means for dissolving a second gas in the liquid to replace the first gas; and separating means for collecting and removing the first gas driven out of solution from the liquid.
Usually, such a reaction would take place in a packed column, where the column packing is designed to provide a large interface area through which mass transfer can take place. Packed columns must therefore be large to provide sufficient interface area. Such large pieces of equipment can be expensive to manufacture and involve high installation costs. In certain applications, such as North Sea oil rigs, the large size of packed columns can add significantly to the cost of a complete platform.